A conventional video cassette recorder ("VCR") incorporates therein a cassette loading device for loading a manually inserted tape cassette to its operative position, and for unloading the loaded tape cassette therefrom. Typically, as shown in FIG. 1, the cassette loading device is provided with a cassette holder 20, a loading arm 30, a linkage lever 40, a bracket 12, and a deck 10.
The bracket 12 is mounted on the deck 10 and has a "L" shaped guide slot 50. The loading arm 30 is provided with a longitudinal slot 32, the longitudinal slot 32 having at one side thereof a cutout 33, a protrusion 38 integrally formed on one side of the loading arm 30, a shaft 34, a pinion 36 partially formed on the loading arm 30 to be engaged with the linkage lever 40, and a torsion spring 39. One end of the spring 39 is supported by the protrusion 38 and the other end of the spring 39 extends across the cutout 33. The shaft 34 protrudes perpendicularly from the center of rotation of the pinion 36 of the loading arm 30. The shaft 34 is rotatably supported by the bracket 12.
The cassette holder 20 is provided with a slider pin 22 fixed to the cassette holder 20 and slidably retained in the guide slot 50 and in the longitudinal slot 32.
The linkage lever 40 is provided with a rack 46 and a lever plane 42. The rack 46 engaged with the pinion 36 is formed on an end part of the linkage lever 40. The lever plane 42 is formed to the right side of the rack 46 on the linkage lever 40. A level of the lever plane 42 is higher than that of a top land of the teeth of the rack 46 on the linkage lever 40.
The linkage lever 40 translates a rotary movement of a motor(not shown) into a rotary movement of the loading arm 30 by traveling leftward rectilinearly, enabling the cassette holder 20 to move from a tape cassette receiving position toward the operative position.
In such a cassette loading device, however, after the tape cassette has been loaded, there is an additional rectilinear movement of the linkage lever 40, allowing the lever plane 42 to additionally rotate the loading arm 30 by pushing the last tooth 37 of the pinion 36. During the additional rotation of the loading arm 30, the slider pin 22 is stopped, when the cassette holder 20 is completely seated on the operative position, and then is resiliently depressed by the torsion spring 39. The resilient depression by the torsion spring 39 prevents the slider pin 22 from further moving or fluctuating.
However, the cassette loading device constructed in this manner has shortcoming in that if it is operated for a long time, the last tooth 37 and a portion of the lever plane 42 coming into contact with the last tooth 37 may become easily worn out due to the friction therebetween, decreasing the force being exerted on the torsion spring 39, which, in turn, reduces the effectiveness of the torsion spring 39.